Last reviewed: 27 September 2026 · By the GSTRisk team · General information, not tax advice.
Every GST registration in India has a 15-character GST Identification Number (GSTIN). Once you know what each part means, you can spot a mistyped or made-up number at a glance.
Example: 27AAPFU0939F1ZV = state code 27 (Maharashtra) + PAN AAPFU0939F + registration number 1 + Z + check character V.
| Characters | Meaning | Example |
|---|---|---|
| 1–2 | State or union territory code | 27 = Maharashtra, 19 = West Bengal, 07 = Delhi |
| 3–12 | PAN of the business (10 characters) | AAPFU0939F |
| 13 | Registration number under that PAN in that state: 1 to 9, then A to Z | 1 = first registration |
| 14 | Letter Z by default for regular registrations | Z |
| 15 | Check character calculated from the first 14 characters | V |
The state code
The first two digits identify the state or union territory where the business is registered. A business with offices in several states needs a separate GSTIN in each, so the same PAN can appear with different state codes. Some common codes:
| Code | State | Code | State |
|---|---|---|---|
| 07 | Delhi | 19 | West Bengal |
| 09 | Uttar Pradesh | 24 | Gujarat |
| 06 | Haryana | 27 | Maharashtra |
| 08 | Rajasthan | 29 | Karnataka |
| 10 | Bihar | 33 | Tamil Nadu |
| 20 | Jharkhand | 36 | Telangana |
| 21 | Odisha | 37 | Andhra Pradesh |
If the state code does not match the supplier’s billing address on the invoice, ask why before you pay.
The PAN and what its 4th letter tells you
Characters 3 to 12 are the business’s Permanent Account Number. The fourth character of a PAN shows the type of holder, which should match how the supplier describes itself:
| 4th letter | Type of holder |
|---|---|
| C | Company |
| F | Firm or LLP |
| P | Individual (for example a sole proprietor) |
| H | Hindu Undivided Family (HUF) |
| T | Trust |
| A | Association of Persons |
| B | Body of Individuals |
| G | Government |
| L | Local authority |
| J | Artificial juridical person |
So a GSTIN whose PAN has P in the fourth position belongs to an individual. If the invoice says “Private Limited”, that is worth questioning.
The 13th character: more than one registration
A business can hold more than one registration under the same PAN in the same state, for example for separate business verticals. The 13th character numbers them: 1 for the first, 2 for the second, and so on up to 9, then letters.
The 14th and 15th characters
The 14th character is Z by default for regular registrations. The 15th is a check character worked out from the first 14 using a fixed formula. Change any one character and the check character no longer matches, which is why a checker can catch most typing mistakes and invented numbers.
GSTINs that do not contain a PAN
A few registrations follow a different pattern. For example, government departments that deduct tax at source register using their TAN (Tax Deduction Account Number) instead of a PAN, and some non-resident and special registrations use different codes. The GSTRisk checker labels these so you know to confirm them on the portal.
What a valid format does not tell you
A correctly formed GSTIN is not proof that the registration is active, that it belongs to the business on the invoice, or that the business files its returns. Always follow the format check with a status check on the GST portal or the live check on GSTRisk. See how to verify a GST number.
Check a supplier now: use the free GSTIN checker for the format and live registration status, or add your whole supplier list to the free supplier watchlist and get an email if a registration changes.